4.A deposition occurs when the product of the concentration of ions is greater than its Ksp.In one experiment, three test tubes, each containing 10 ml of 0.01 M solution of CaCl2, and BaCl2 SrCl2, each tube is added 10 ml solution of 0.01 M K2SO4If Ksp CaSO4 = 2 x 10-4; SrSO4 = 2 x 10-7; BaSO4 = 9 x 10-11, then the salt buildup is ....A.BaSO4B.CaSO4 and SrSO4C.CaSO4 and BaSO4D.SrSO4 and BaSO4E.CaSO4, BaSO4, and SrSO4

5.Relative molecular mass of the solute can be determined if the pressureosmotic and temperature of the solution and the solute mass is known.A total of 1.27 grams of electrolyte substances dissolved LCl2 at 270 Cin water until the volume of 500 ml.solution osmotic pressure = 1.476 atmand R = 0.082 l atm / mol.K then Mr. electrolyte substance is ....A.127B.172

7.In (T, P) the same mixture of gases consisting of methane (CH4) and ethane (C2H6) 10 liters of gas burned perfectly with 26 liters of oxygen gas, producing CO2 and water vapor, the composition of the gas mixture consists of:A. 3 liters of CH4­ and 7 liters of C2H6B.4 liters of CH4 and 6 liters of C2H6C.5 liters of CH4 and 5 liters of C2H6D.7 liters of CH4 and 3 liters of C2H6E.6 liters of CH4 and 4 liters of C2H6

8.9 grams aluminum 8 grams of appropriate action with oxygen to form 17 grams Al2O3.If, after the reaction is obtained 102 grams of aluminum oxide and 15 grams of residual aluminum.So the first first aluminum mass is :A.20 gramsB.40 gramsC.48 grams

10. Mass ratio of calcium and oxygen in the form of calcium oxide is 5: 2.If 10 grams of calcium is reacted with 5 grams of oxygen, the calcium oxide formed is:A.5 gramsB.10 gramsC.14 gramsD.15 grams

E.20 grams

11.For complete combustion of C2H4 at 10 liters (T, P) the same produce CO2 and water vapor.If the oxygen levels in the air 20% of the air needed for combustion is ....A.50 litersB.75 litersC.100 literD. 125 liters

E.150 liters

12.Known 5.6 liters of XO3 gas (STP) has a mass of 20 grams. So the relative atomic mass of X is ....(O = 16)A.16B.24C.32D.40E.64